1. Field of the Invention
The present invention relates to a method for a convenient and operator-friendly selection of a direct radiographic panel as active DR Panel for a radiographic exposure.
2. Description of the Related Art
It is known that radiographic illumination or exposure has important applications in medical imaging, whereby the medical advantages for the patient largely exceed the small risk of damage resulting from such radiographic illumination.
In earlier days radiographic exposures mostly made use of film based on silver halide technology as image capturing medium.
Since a number of years the so-called computed radiography technique has gained wide market acceptance. This technology makes use of a radiographic panel that does not use silver halide technology as the light capturing medium, but uses stimulable phosphors.
This method is described amongst others in detail in the Handbook of Medical Imaging, (ed. R. V. Matter et al., SPIE Press, Bellingham, 2000).
During recent years, radiographic exposures increasingly make use of direct digital radiographic techniques, known as DR (Direct Radiography).
This method is increasingly used as alternative for film-based imaging techniques, as well as for the panels based on the use of stimulable phosphor-technologies, as described supra.
In this digital radiographic method the radiographic exposure energy is captured pixelwise in a radiographycally sensitive panel, and hereupon is converted to electronic image data by electronic components. Hereupon the information is read out imagewise and displayed on a suitable monitor for diagnostic purposes by a radiologist.
One of the driving forces behind the success of direct digital radiography is the ability to rapidly visualise the radiographic images and to efficiently and simply communicate over data networks to one or more sites for analysis and remote diagnosis by a radiologist or other medical expert. The delays that are characteristic for the development, packaging and physical transport of radiographic films are avoided by the above methods. Also the difficulties arising from the scanning of developed films and the corresponding loss in resolution is avoided by the above techniques.
The advantage of direct radiographic systems over computed radiographic systems, based on stimulable phosphors, is that no read-out (in a digitizer) of the latently captured radiographic image needs to take place. On the contrary, the digital radiographic image promptly or directly can be read for the purpose of evaluating the image from a diagnostic point of view. This diagnosis can take place at a local or remote workstation.
At the beginning the first direct radiographic panels were integrated in the overall radiographic imaging system. The wiring was designed such that minimal trouble to the radiographic operator was caused hereby when the radiographic direct panel was placed for exposure of a body part of a patient. More recently portable direct radiographic panels have been introduced to the market place. These panels make use of an on-board battery and communicate with the radiographic control panel or workstation, as well as with the data capturing apparatus and the display components in a wireless manner.
The latter aspects resulted in a wide acceptance of such portable wireless panels by the marketplace and ensures their practical use in a fully digital radiographic exposure system.
In a hospital or medical diagnosis center, these panels can be used as well in a completely newly installed radiographic imaging system or in a so-called retrofit situation. The term retrofit should be understood as directed to an existing radiographic system, that previously made use of radiographic films or stimulable phosphor plates, and whereby the latter registration media have been replaced by a direct radiographic capturing medium, a so-called direct radiographic or DR panel, without the need to replace the workstation or the radiographic source itself. The advantage of such a retrofit radiographic system as compared to a completely newly installed radiographic system, is its lower investment cost, as part of the already installed radiographic system can be re-used.
Although portability and wireless communication of the radiographic registration medium clearly is an advantage when portable and wireless DR panels are used, these features also are characterized by the occurrence of problems under practical circumstances of use. In particular such panels are characterized by identification or selection difficulties when they are used in a so-called multi-panel environment. This may lead to mistakes for example when resetting the correct panel, or the wrong use of a panel.
Contrary to radiographic films or stimulable phosphor panels that after exposure need to be removed from the radiographic exposure room for the purpose of being developed, resp. for being read-out in a digitizer, direct radiographic panels after use can remain in the radiographic exposure room.
When as a result of the above situation various direct radiographic panels are available in the radiographic exposure room, the radiographic operator needs to be fully sure that for the next or forthcoming radiographic exposure the right panel needs to be identified or selected.
Absent same it would be possible to address the wrong DR Panel, or to reset same, or the collect the data hereof.
Without a specific method that enables to reduce to an absolute minimum the probability of choosing a wrong DR Detector, there remains an enhanced risk for an incorrect exposure of a patient, resulting in retakes. On its turn, this results in a number of complaints, confusion, and a loss of time and efforts.
To cope with the above problems, Canon Inc., USA, has developed the following identification or selection method for direct radiographic panels, which it recommends for daily use. In the leaflet entitled ‘Canon CXDI-70C Wireless Premium Flat Panel Detector’, edited by Canon Medical Systems, A Division of Canon U.S.A. Inc., 15955 Alton Parkway, Irvine, Calif., USA, with reference DRB-014 Rev. A, 0611/2000, website www.usa.canon.com/csdi-70cwireless, a method for the identification/selection of digital radiographic panels has been described.
(In the text that follows, both terms ‘identification’ or ‘selection’ of a direct radiographic panel is used, both terms having the same meaning.) The method described therein is as follows:
On the digital radiographic DR Canon Panels an infrared transmitter/sender is provided with pressure-sensitive button. This is the so-called IR check-in unit.
When a radiographic operator takes the Canon digital radiographic panel out of its docking station, he holds this panel on short distance before a radiographic workstation, wherein an infrared receiver is positioned.
Hereupon he pushes the IR pressure button, and the link to the radiographic workstation is unequivocally established.
As a result hereof the captioned direct radiographic panel is unambiguously and unmistakably identified and is ready for being used in the digital radiographic exposure unit.
During such identification the DR Panel receives the WIFI settings that are required to enable it to work in the setting of the radiographic workstation.
To this end, a fixed IP address, an SSID (Service Set Identifier) and a WPA-PSK (Wi-Fi Protected Access, Pre-Shared Key) of the access point and the IP address of the radiographic workstation is allocated to the DR Panel concerned.
The activation of the DR Panel as described above occurs in the Canon method by selecting the captioned panel on the workstation.
In US patent publication nr. US 2011/0116486 A1, published on May 19, 2011, in the name of Canon Kabushiki Kaisha, Tokyo, Japan, reference is made to the use of portable and wireless direct radiographic panels, and the identification of such panels by means of such infrared communication. For the purpose of identification of the DR Panel, ‘an input unit is provided for the X-ray sensor apparatus and accepts input from the user’. (Paragraph 33) Further in paragraph 35 is stated that ‘pressing the input unit of the X-ray sensor apparatus will start connection processing of the X-ray sensor apparatus to the access point.’ The term ‘pressing the input unit’ is repeatedly used in this specification, see e.g. par. 41, 4° line, par. 47, 5° Line, par. 51, 2° line, par 55 last but one line, etc.
Upon pressing the input unit, the wireless communication starts, based on the use of IrDA, Transferjet or UWB (paragraph 33).
In European patent publication nr. EP 2 062 533 A1, published on May 27, 2009, in the name of Carestream Health, Inc., a method is also described for the identification, resp. the activation of direct radiographic panels. Hereby use is made of marking labels that are attached to the direct radiographic panels, whereby an operator, for example the radiologist or one of his assistants, activates the correct direct radiographic panel by means of the touch screen of the radiographic workstation.
This procedure however is also quite cumbersome: it implies that for each radiographic exposure the radiographic operator should go to the radiographic workstation, and there needs to navigate to the screen that shows the various possibly active DR Panels, and should then designate the correct panel by touching the correct field on the touch screen of the display.
In US Patent Application US 2010/0169423 A1, published Jul. 1, 2010, in the name of Konica Minolta Medical & Graphic, Inc, Tokyo, Japan, a radiographic image capturing systems is described, wherein a Flat Panel Detector (FPD) is activated and its IP address is communicated to the radiographic console, by means of pressing a pressure button by the radiographic operator. Reference is made to paragraph 58 stating that ‘the operator depresses the button equipped on the FPD concerned . . . ’
In US Patent Application US 2010/0123083 A1, published May 20, 2010, in the name of General Electric Company, NY, USA, an imaging system is provided, wherein the portable digital image detector may be configured to communicate its location to the system control circuitry. To that end, the digital detector may include various sensors and mechanisms configured to enable the system to determine the location of the detector (paragraph 28). The sensors may be mechanical sensors physically activated by engagement with actuators, or may include induction sensors triggered by proximity to the corresponding actuators.
Through such mechanism, the imaging system may detect the presence of a digital detector in e.g. its table or wall stand. Paragraph 31 discloses the use of a button or switch ‘that may be engaged by a technician or other user’.
Apart from detecting the position of the digital detector, this specification discloses no other function associated with such actuators or sensors on the digital detector.
In US Patent Application US 2011/0274251 A1, published Nov. 10, 2011, in the name of General Electric Company, NY, USA, a method is described for coordinating operation of X-ray detectors in a wireless X-ray system, including detecting multiple wireless X-ray detectors within an operative range of an X-ray base station. Paragraph 24 of this specification discloses to this end the use of a button that may be pressed in response to instructions received from the X-ray base station to select the detector for registration.
In US Patent Application US 2011/0305319 A1, published Dec. 15, 2011, in the name of General Electric Company, NY, USA, a portable x-ray detector and a gravity sensor coupled thereto is described. A processor is coupled to the gravity sensor, programmed to receive an input from the gravity sensor, determine a physical orientation of the portable x-ray detector based on the received input, and generate an indication to reposition the portable x-ray detector. The aim of such gravity sensor and coupled processor is to solve the problem when the operator positions the x-ray detector out of alignment with respect to the x-ray source.
Apart from the above, this specification discloses no other function associated with such gravity sensor and its coupled processor.
The method as described above with the Canon detectors gives rise to problems under practical use: the method is quite cumbersome, and hence it occurs that this procedure is not applied, in particular in emergency situations. Same applies to the method described in the Carestream patent application, or to the methods described in the Konica & Minolta patent application, or any of the other cited patent publications.
On top hereof, these methods may well be suitable when one DR panel is in use in a given radiographic exposure room, but the method gives rise to problems when more DR panels simultaneously are available for use.
In a radiographic exposure room, in many cases various DR Detectors are used, as they differ for example in their respective sizes.
When a radiographic exposure is prepared from the central radiographic workstation or console, the correct panel should be selected for the forthcoming exposure. To this end an unambiguous link is required between the radiographic exposure as planned and the corresponding DR Panel.
As set forth supra, when the radiographic operator has selected the wrong DR Panel, the radiographic exposure cannot be effected correctly.
When the wrong panel is linked to the workstation, as soon as the exposure button has been activated, the wrong panel will start to integrate. This implies loss of image data.